As one of the alternatives for overcoming a limited abundance of land resources, technology for recovering trace amounts of useful resources from seawater or brine has been actively developed. The seawater or brine of which reserves are infinite has an advantage in view of abundance, but various matrix ions are present therein, and concentrations of the useful resources to be recovered such as lithium, strontium, boron, or the like, are relatively low, such that it is essential to develop a technology capable of selectively separating these useful resources.
It was reported that among methods for selectively separating a target material having a low concentration, a method using adsorption is most efficient. Therefore, it is most important to develop highly efficient and highly selective adsorbent material.
Particularly, a recovery method using a manganese oxide based inorganic adsorbent having highly selective ion exchange characteristics has been widely used as one of the most preferable methods, and thus, various manganese oxide based inorganic adsorbents have been developed.
For example, a technology of recovering useful metals from concentrated water using a manganese oxide based inorganic adsorbent has been disclosed in Korean Patent No. 10-1238898 (Patent Document 1). This technology, which may adsorb the lithium ions in a liquid by ion exchange between hydrogen ions and lithium ions in the liquid containing the lithium ions, that is, topotactic extraction and then recover the lithium ion from an inorganic adsorbent adsorbing the lithium ion through ion exchange between hydrogen ions and the lithium ion in a dilute aqueous hydrochloric acid solution, has an advantage in that the manganese oxide based inorganic adsorbent may be repetitively used.
However, since these inorganic adsorbents according to the related art are prepared in a form of powder, in order to actually apply these inorganic adsorbents to a recovery process, a solid-liquid separation device or a formation and assembling technology for fixation has been required. In the case of using a solid-liquid separation device according to the related art such as a device for filtration and centrifugation, there are disadvantages in that a process may be complicated, a loss of an adsorbent material may be incurred, and a process time may also be increased, and in case of using a formed and assembled adsorbent, there is a disadvantage in that adsorption performance may be deteriorated as compared to a powdery adsorbent material. Therefore, a process technology capable of applying a powdery adsorbent material as it is to improve recovery efficiency has been required.